hachoir-metadata extracts metadata from multimedia files: music, picture, video,
but also archives.  It tries to give as much information as possible. For some
file formats, it gives more information than libextractor for example, such as
the RIFF parser, which can extract creation date, software used to generate the
file, etc. But hachoir-metadata cannot guess informations. The most complex
operation is just to compute duration of a music using frame size and file size.
